Modulating door check

ABSTRACT

1,124,000. Door closing device comprising a modulating door check. VAPOR CORP. 13 June, 1967 [12 Sept., 1966], No. 27246/67. Heading E2M. A door closing device 13 having application in vehicles having passenger/driver operated doors, is illustrated with reference to drawings (see Figs. 1, 2 and 3) and comprises a spring 21 for closing the door 11 and a check device 33 for modulating the closing action, said check 33 including a cylinder 35 having a piston 39 and a rod 32 connected to the door, and having a one-way air valve means 46 intercommunicating the opposite sides of the piston when it is moving toward the closed end of the cylinder during door opening and said valve closing during door closing, a continuously open orifice 50 bleeding air between opposite sides of the piston, an air control hole 52, 53 in the rod end of the cylinder, and means 56, 57 for breaking the seal of the piston with the cylinder wall and enabling air to readily pass between opposite sides of the cylinder allowing fast movement of the piston toward the rod end of the cylinder over a predetermined distance. The device enables the provision of a door closing action made up of a pause as the door starts to close, followed by a fast movement to a position where the door is cushioned before finally being snapped shut.

April 30, 1968 y u mD s ET AL MODULATING DOOR CHECK 2 Sheets-Sheet 1 Filed Sept. 12, 1966 INVENTORS KRISTUPAS DAUGIRDAS ROBERT J. LYNN S LEO ATTORNEY April 30,1968 u m s ET AL 3,380,110

MODULATING DOOR CHECK Filed Sept. 12, 1966 2 Sheets-Sheet 2 INVENTORS KRISTUPAS DAUGIRDAS ROBERT J, LYNN S. LEO LOWY fi-v ATTORNEY vm mm United States Patent 3,380,110 MODULATING DOOR CHECK Kristupas Daugirdas, Wilmette, Robert J. Lynn, Morton Grove, and S Leo Lowy, Chicago, Ill., assignors to Vapor Corporation, Chicago, Ill., a corporation of Delaware Filed Sept. 12, 1966, Ser. No. 578,561 2 Claims. (CI. 16-66) ABSTRACT OF THE DISCLOSURE Modulating door check for controlling the closing action of a vehicle door normally opened by egressing passengers including a cylinder having a piston movable therein, wherein a flap valve is provided in the piston to permit uninhibited movement thereof toward the closed end, an orifice is provided in the piston for bleeding air during door closing action, an orifice is provided in the rod end of the cylinder tobleed air from the rod side of the piston during door closing action, and piston seal breaking means is provided in the cylinder Wall to aid in controlling door closing action.

This invention relates in generalto a door closing device, and more particularly to a modulating door check employed in a door closing device, and still more particularly to a modulating door check useful for controlling door closing action for doors employed on passenger carrying vehicles that are opened by a passenger during egress from the vehicle, although other uses and purposes may be apparent to those skilled in the art.

The modulating door check of the invention is especially useful in a door closing device employed in a passenger carying vehicle where the doors are normally opened by the passengers during egress from the vehicle. It is quite common to have the rear doors on a passenger bus mounted for opening by the passengers during egress from the bus, and such doors are provided with a door closing device that operates to close the doors after the passenger has released the doors from the open position. Such door closing devices include door checks in combination with springs which power the doors to a closed position, but heretofore known door checks have been unsatisfactory since they have included needle valves and troublesome ball check valves. Since a door check controls the door closing speed and a vehicle cannot move until the doors are in fully closed position, some drivers have been known togreatly increase the door closing speeds on heretofore used door checks having needle and ball check valves so that they can make faster getaways from stops and reduce the running time between terminals. Such an increase in closing speed nearly always results in causing the doors to slam which is injurious to the doors and door closing mechanism causing early maintenance and/ or repair. Further, heretofore known door checks generate considerable back pressure in the door closing mechanism during opening of the door thereby making it more difficult for a passenger to open the doors, either from a fully closed position or a partially closed position.

The modulating door check of the present invention is adapted to be used in known door closing mechanisms-for self-closing doors, while serving to precisely control door closing action, and even modulating the door closing movement so that the best possible door action consistent Wtih passenger egressing is obtained. Further, the door check of the present invention is not adjustable, and therefore cannot be tampered with by the drivers, and controls door closing movement in order to eliminate possible equipment abuse thereby extending the life of the equipment.

3,380,l 10 Patented Apr. 30, 1968 "ice It is therefore an object of the present invention to provide a new and improved door check for use in a door closing device.

Another object of this invention is in the provision of a modulating door check that precisely controls door closing action in a manner to extend the life of the doors and associated mechanism and to better facilitate the egressing of passengers through the doors.

Still another object of this invention resides in the provision of a modulating door check for use in the door closing device employed in passenger carrying vehicles such as buses, wherein door closing movement is closely controlled while door slamming is eliminated.

A furtherobject of this invention is to provide a modulating door check for a door closing device to be employed on passenger carrying vehicles which is capable of producing a pause in door closing action as the door starts to closefrom a fully opened position ahead of a fast movement to a position where the door is cushioned before being fully closed, and to provide a final snap shut action to the fully closed position.

A still further object of this invention is in the provision of a modulating door check for use in a selfpowered door closing device, wherein needle and ball check valves have been eliminated, a fewer number of parts are employed over heretofore known door checks, manufacturing costs have been reduced, and maintenance requirements have been lessened.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a fragmentary elevational view of the side of a vehicle having a set of doors to be opened by passengers and illustrating the arrangement of a door closing mechanism in block form for the doors which employs the modulating door check of the present invention;

FIG. 2 is a somewhat schematic top plan view of a door closing mechanism for use on doors of a vehicle such as shown in FIG. 1, and illustrating the position of the modulating door check of the present invention;

FIG. 3 is an axial sectional view taken through the door check of the present invention and showing the piston in full lines in the position attained when the doors are closed;

FIG. 4 is a cross sectional view taken through the piston of the door check of the present invention, and taken substantially along line 44 of FIG. 3;

FIG. 5 is a plan view of the cylinder for the door check of the present invention, removed for purposes of clarity, and illustrating the position of the grooves formed in the cylinder Wall; and

FIG. 6 is a diagrammatic showing of the door closing movement to illustrate the modulating door closing action.

Referring now to the drawings, and particularly to FIG. 1, a vehicle 10 for transporting passengers is shown with a pair of outwardly swinging doors 11 arranged in the side wall 12, the closing action of which is controlled by the door closing device or mechanism 13 illustrated in block phantom. The doors 11 are mounted on vertically extending shafts 14, suitably bearingly supported at their upper and lower ends, and coupled to the door closing mechanism 13 at their upper ends Which effects control of the doors during closing movement. 7

The door closing mechanism 13, as seen in FIG. 2, includes generally a main shaft 15 arranged vertically and suitably bearingly supported. A teeter lever 16 is secured to the shaft for rotation therewith, and is pivotally connected at opposite ends to connecting rods 17 that are in turn pivotally connected to brackets 18 that are secured to the doors 11, whereby pressure against either door 11 to move it to open position simultaneously through the connecting rods 17 and teeter bar 16 causes opening movement of the other door 11. Lugs 18a are formed on the brackets 18 which engage stops 19 when the doors are in fully open position as shown in dotted lines for limiting the opening movement. Thus, opening of one door 11 causes opening of the other door at the same time and the doors can only be opened to a predetermined position.

A cam plate 20 is also secured to and rotatable with the main shaft 15. In order to supply power to close the doors 11, a heavy extension spring 21 is attached at one end to a pin 22 on the cam plate 20 and at the other end to a fixed bracket 23, whereby a moment arm is established through the cam plate 20 on the main shaft 15 for applying closing power to the doors when they are in open position and also for holding the doors in closed position. It should be appreciated that the power of the spring 21 may be adjusted or the spring may be easily changed depending upon the closing force desired for the doors 11. Further, the connecting rod 17 may be adjusted to properly position the doors in their closed position.

In order to prevent opening of the doors when the vehicle is in motion, a locking mechanism including a latch 24 pivotally mounted on a shaft 25 coacts with the cam plate 20 to prevent rotation of the main shaft 15. A spring 26 is provided to continually urge the latch 24 against a stop 27 which places the latch in interfering position to a nose portion 28 of the cam plate 20 to prevent rotation of the cam plate and shaft 15 in the direction to cause opening of the doors 11. When the driver of the vehicle is halted for allowing egressing of passengers from the vehicle, he may energize a solenoid 29 to cause a plunger 30 to rotate the latch 24 in a counter clockwise direction against the force of the spring 26 and out of interference with the nose portion 28 of the cam plate 20 to thereby allow rotation of the cam plate and cam shaft 15 and opening of the doors 11. When the solenoid 20 is tie-energized and the cam plate 20 again attains the position shown in FIG. 2, the latch 24 moves to locking position against the stop 27 to again block movement of the cam plate 20 and shaft 15. Any other type of locking mechanism may be provided.

A crank arm 31 is also mounted on the main shaft 15 for rotation therewith and is pivotally connected at its outer end to a rod 32 of the door check 33 that comprises the present invention. The door check 33 is piv otally anchored on a fixed pin 34. It will be understood that the door closing mechanism 13 is of a type heretofore generally known, and that the door check 33 is the improvement in the door closing mechanism and therefore comprises the present invention.

Referring now to FIGS. 2-5, the door check 33 includes a cylinder 35 having opposed end caps 36 and 37 suitably tied together by fasteners 38 at each end thereof. A piston assembly 39 is slidably received within the cylinder 35 and secured on the inner end of the rod 32 which is bearingly supported in the end cap 36. The inner end of the rod 32 is shouldered to receive the piston 40 of the piston assembly, and a nut 41 is threadedly received on the end of the rod to securely fasten the piston 40 thereto. The external diameter of the piston 40 is slightly less than the internal diameter of the cylinder 35, anda piston cup 42 is received in an annular groove 43 formed in the outer periphery of the piston. The piston cup is provided with an O-ring 44 which expands the cup and causes firm sealing engagement between the cup and inner wall surface of the cylinder 35.

Movement of the piston assembly 39 toward the end cap 37 is unrestrained and easy due to a plurality of axially extending holes 45 being formed in the piston 40 which allow substantially unrestricted movement of air from one side of the piston to the other side. During movement of the piston assembly 39 from the closed end of the cylinder to the rod end, a flapper valve 46 seals .4 the holes 45 and prevents the movement of air therethrough between opposite sides of the piston. The flapper valve 46 is in the form of a resilient washer, such as of rubber, that freely fits over the rod 32. A thin metal washer 47 backs up the flapper valve 46 and is prevented from unrestricted movement along the rod 32 by an E- ring 48 locked into an annular groove 49 on the rod. Sufficient movement is allowed the flapper valve 46 to permit complete opening of the piston toward the closed end of the cylinder.

A small fixed orifice 50 is provided in the piston 40 and in continual communication with both sides of the piston. A counterbore 51 extends inwardly from the rod side of the piston to the orifice 50 and is arranged so that it is not covered by the flapper valve 46 when the piston moves toward the closed end of the cylinder. Thus, on movement of the piston from the closed end toward the rod end, air is transferred through the orifice 50 to control the rate of movement of the piston.

To further control piston movement, an orifice 52 is provided in the end cap 36 at the bottom of a counterbore 53. This orifice also serves to replenish air lost during the cycle. In order to prevent contaminants from entering the cylinder, at filter 54 is mounted in counterbore 55 leading to the counterbore 53 and the orifice 52, whereby air entering the cylinder on the rod side of the piston through the orifice 52 is filtered.

In order to further control movement of the piston assembly 39 and piston rod 32 toward the rod end of the cylinder so as to properly control door closing movement, a pair of axially spaced pockets or grooves 56 and 57 are formed in the wall of the cylinder 35 to cause air flow intercommunication between opposite sides of the piston 40 when the piston cup 42 passes thereover to the extent that door closing speed is set. While a pair of grooves 56 and 57 are shown, a single groove could be employed within the scope of the present invention in order to control the closing action. A third groove or pocket 58 is formed in the wall of the cylinder 35 closely adjacent to the rod end of the cylinder to define the snap shut closing action of the doors by releasing the differential air pressure between the opposite sides of the piston when the piston cup passes thereover.

Referring now to FIG. 6, the door is shown in closed position and designated 11a, and in open position designated by the numeral 11b. Applying pressure on either door 11 to move them to open position from the position 11a to the position 11b causes the piston assembly 39 to move toward the closed end of the cylinder adjacent to the end cap 37. A counterbore 59 is provided in the closed end of the cylinder to facilitate receiving the protruding portion of the piston rod assembly, and a resilient stop 60 is provided in the bottom of the counterbore to cushion against an unexpected bottoming of the piston. During movement of the piston assembly 39 toward the closed end of the cylinder, the flapper valve 46 moves away from the rod end of the bypass holes 45 to freely allow the passing of air between opposite sides of the piston. Heretofore, it was necessary to move the piston assembly against needle and/or ball check valves, wherein the present invention permits much easier movement of the piston and therefore requires less power by a passenger egressing through the doors 11. Further, since air is allowed to freely pass from one side of the piston to the other side of the piston, the air within the cylinder is utilized and there is need for very little additional air to be provided therein through the orifice 52 which precludes the possibility of allowing unwanted contaminants within the cylinder.

Upon release of pressure on the doors 11 by the passenger, the spring 21 applies a force to the doors in a closing direction which is opposed by the door check 33. Because the flapper valve 46 now closes the holes 45 extending between both sides of the piston, the orifice 50 is then brought into action. Immediate movement of the piston assembly 39 toward the rod end of the cylinder efi'ects rarefying of the air at the closed end cap side of the piston causing a pause in the door closing movement and a slow closing movement between the positions 11b and 110 as seen in FIG. 6. The piston cup 42 when passing over the groove 56 loses its seal with the cylinder wall whereby a fast movement of the piston toward the rod end of the cylinder is produced between the positions 110 and 11d. The seal of the piston cup is again made as the leading edge of the piston cup passes over the rod end of the groove 56 to again slow the movement of the piston toward the rod end between the door positions 11d and He. The piston cup 42 then moves across the pocket or groove 57 and again loses its seal with the cylinder wall, allowing air to readily pass between opposite sides of the piston thereby resulting in a fast movement of the piston toward the rod end of the cylinder from the position He to the position 11]. As the leading edge of the piston cup completes its travel across the pocket or groove 57, sealing action with the cylinder wall is once again established to again build up pressure differential and effectively maintain the same speed of the piston until the doors reach the position 11g. During movement from the pocket 57, the orifice 50 again functions to allow a controlled air movement between opposite sides of the piston. The orifice 52 in the end cap 36 now becomes active also, restricting the bleed of the air from the cylinder, thus resulting in increased pressure differential to provide cushioning action near the fully closed position of the doors. Just ahead of the fully closed position, the piston cup 42 comes under the influence of the pocket 58 allowing quick air transfer between opposite sides of the pistons so that the doors can snap into the fully closed position. However this movement does not result in slamming of the doors.

Thus, it can be seen that the dimensions of the pockets 56, 57 and 58, together with the diameter of the orifice 50 coact with the closing force supplied by the spring to establish the closing speed of the doors, yet this predetermined closing speed cannot be significantly changed by the driver of the vehicle. Indeed, the dimension of the pockets, once established, cannot be changed and therefore control of the doors will always be present. The closing cycle as illustrated generally in FIG. 6 merely represents diagrammatically the closing action provided by the preferred embodiment disclosed, and it should be appreciated that this closing action could be changed by placement of the pockets in other positions along the cylinder, difierent sizing of the orifice 50, and different sizing of the closing spring. Further, as already mentioned, a single pocket may be provided instead of a pair of pockets at the end of the cylinder adjacent to the closed end for establishing the closing speed following the pause.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. In a door closing device having a spring for supplying power to close a door and a check device for opposing the action of the spring and modulating the closing action of the door, said check device including an anchored cylinder having a piston sli-dable therein and connected to a piston rod extending from one end of the cylinder, said piston rod being connected to said door, said piston having opening means therethrough closable by a flapper valve positioned on the rod side of the piston when the piston is moving toward the rod end of the cylinder, said flapper v-alve and opening means operable to open and allow substantially unrestricted movement of said piston during movement thereof toward the closed end of the cylinder during door opening and to close during movement toward the rod end of the cylinder during door closing, a continuously open orifice extending through said piston for continuously bleeding air between opposite sides thereof at a controlled rate, an air control hole in the rod end of the cylinder, and means for breaking the seal of the piston with the cylinder wall and enabling air to readily pass between opposite sides of the piston including an elongated recess along the inner cylinder wall sized to release the seal of the piston with the cylinder and intercommunicate both sides of the piston when it travels thereover toward the r-od and during door closing and allow fast movement of the piston for a predetermined distance.

2. In a door closing device having a spring for supplying power to close a door and a check device for opposing the action of the spring and modulating the closing action of the door, said check device including an anchored cylinder having a piston slidable therein and connected to a piston rod extending from one end of the cylinder, said piston rod being connected to said door, said piston having opening means therethrough closable by a flapper valve positionad on the rod side of the piston when the piston is moving toward the rod end of the cylin-der, said flapper valve and opening means operable to open and allow substantially unrestricted movement of said piston during movement thereof toward the closed end of the cylinder during door opening and to close during movement toward the rod end of the cylinder during door closing, a continuously open orifice extending through said piston for continuously bleeding air between opposite sides thereof at a controlled rate, an air control hole in the rod end of the cylinder, and means for breaking the seal of the piston with the cylinder wall and enabling air to readily pass between opposite sides of the piston including a pair of longitudinally extending and spaced elongated recesses adjacent the closed end along the inner cylinder wall sized to release the seal of the piston with the cylinder wall and intercommunicate both sides of the piston when it travels thereover toward the rod end during door closing and allow fast movement of the pison for a predetermined distance, said pair of recesses being spaced a sufficient distance from the closed end of the cylinder to first permit a pause in door closing action as the piston moves toward the rod end of the cylinder, said pair of recesses setting the door closing speed for most of the door closing movement, and an elongated longitudinally extending recess closely adjacent the rod end along the inner cylinder wall sized to release the seal of the piston with the cylinder wall and intercommunicate both sides of the piston when it travels thereover toward the rod end during door closing to allow fast movement of the piston for a predetermined distance and efiect a snap shut closing action for the door.

References Cited UNITED STATES PATENTS 266,795 10/ 1882 Elliott 16-70 1,471,560 10/ 1923 Langford 16-84 XR 2,064,995 12/1936 Van Arsdel 16-84 2,119,589 6/1938 Lutz 16-84 2,543,565 2/1951 Billingsley 16-6'6 2,665,447 1/1954 Lovejoy 16-66 X-R 2,839,777 6/1958 Parsons et al. 16-66 2,920,338 1/1960 Falk 16-66 3,010,433 11/1961 C-odling i 16-66 XR 3,020,581 2/1962 Falk 16-66 3,059,269 10/1962 Selinger et al 16-84 X-R FOREIGN PATENTS 1,314,466 12/1962 France.

BOBBY R. GAY, Primary Examiner.

JAMES L. KOHNEN, Assistant Examiner. 

